Effect Of Different N Fertilizer Rate On Cotton

A field experiment was conducted from 2009-2010,in Huazhong Agricultural University to study the effect of nitrogen rate of cotton on the yield, agronomic traits,physiological characters and soil nutrients,by adopting Xiang Hybrid No.8 and H318.1 The accumulation and distribution of cotton materialThe dry matter with the lapse of time increase gradually.accumulation of dry matter increase with the increasing N fertilizer rate.the yield of F5 was the maximum (273.18g/per),F1 was the lowest(193.8g/per).With the process of cotton growth, the dry matter of reproductive organ just being up, the dry matter of vegetative organ increased at first and declined later.2 Impact of physiological and biochemical index of cottonTwo experimental plants function spad leaves in the same value trends the SPAD values of function leaf was increase with the increasing N fertilizer rate.The SPAD values was drop down in the beginning of august,because the process of organic accumulate was over, and cotton turn to reproductive growth.Soluble sugar and protein content of different treatment showed same trend.They all increased at first and declined later, the effect of N level was is significant between F1 and F5.Total N conytent of leavev is between 2%～5%,increase with the N fertilizer rate.3 Impact of cotton agronomic traitsThe agronomic traits is increase with the increasing of N level.The result showed that N fertilizer peomote the development of cotton bolls, branches,and fruits. With the process of cotton growth,the number of green leaves and bolls increased at first and declined later.4 Impact on yieldN fertilizer could increase the yield of cotton, the cotton yield of F5 was the maximum,166.2kg/667m2.yield of organic fertilizer treatment was 152.3kg/667m2.Is significant prove the yield.accord with the AE formula, the relationship of different treatment in HZAU is F2>F3>F4>F5. The relationship of different treatment in EZHOU is L10-20cm>20-30cm.and nutrition within 20cm depth are the main sourse of plant. Variation of available phosphorus and potassium of 0-10cm depth were both greater than other two depth.